This invention relates to telecommunications systems and in particular to a telecommunications system for controlling the routing of telephone traffic based on the telephone number of the calling station.
Most telephone calls typically access the long distance network from shared facilities, such as a public switched network. As shown in FIG. 1, a long distance call is originated from either a land-line calling station 100 or a wireless calling station 102. The call is sent to the local exchange carrier (LEC) switching office 104 via trunks 101 or 103. From the LEC switching office 104, the long distance call is routed, via a trunk 105, to a long distance carrier switching office 106, hereinafter referred to as a switch. The call may then be routed to another switch 108 if needed to complete the communication. The LEC switching office 104 sends the caller""s automatic number identification (ANI), i.e., the origination phone number, and the destination address to the switch 106. If the destination address is an 800 number, the call progresses through the normal routing to its destination. However, if the destination address is private, direct distance dialing (DDD), or international direct distance dialing (IDDD), the caller""s ANI is checked in the switch 106 for any restrictions or processing enhancements that are required for this particular caller. Based on applicable restrictions, the caller may be blocked from making this call, sent to an operator, prompted for account codes, routed to the desired destination, etc.
Currently, the ANI screening is performed in the switch 106. The ANI screening table, located in the switch 106, typically contains only the ANIs active in that local area, i.e., the ANIs for only three or four area codes, known as numbering plan areas (NPA). If a particular ANI has no restrictions, it is not contained in the ANI screening table of the switch 106.
When a cellular phone accesses the long distance carrier network, its ANI is processed the same way as the land-line ANI. The problem arises, however, when the cellular roamer is originating a call outside its serving area. Due to prohibitive memory requirements, all cellular ANIs cannot be loaded in each long distance carrier switch. The switch 106, therefore, cannot provide adequate screening for every caller. If the roamer""s ANI is received, the call must be processed with no restrictions. This situation causes problems in the long distance carrier network. Virtual private network (Vnet(copyright)) cellular customers can not be identified when they are roaming outside their serving area, and can not use their Vnet(copyright) dialing plans. In addition, identification of calls from fraudulent users is virtually impossible.
To summarize, the current ANI screening cannot process ANIs for calls which originate from outside the local serving area (LSA), such as cellular and personal communications service (PCS) traffic. The amount of memory in the switch required to include all non-local ANIs would be extremely large and cost prohibitive. A need therefore exists for a telecommunications system which provides ANI screening for land-line and wireless telephone calls which originate in, as well as outside, the local serving area.
It is therefore an object of the invention to provide a telecommunications system for screening and processing ANIs from local and non-local areas.
It is another object of the invention to provide a telecommunications system for screening ANIs for cellular and PCS customers.
It is yet another object of the invention to provide a telecommunications system for screening and processing ANIs from a single common location.
These and other objects, features, and advantages are accomplished by a remote telecommunications system for automatic number identification screening.
When a calling station originates a telephone call to a called station, the call is routed via a shared facility to a long distance carrier switch. The switch is served by a network control system (NCS) which serves a plurality of long distance switches. The network control system includes a database and a control manager for screening an automatic number identification of the calling station. Responding to the request from the switch, the network control system provides an identifying information to the switch for ascertaining call type characteristics of the telephone call based on its automatic number identification.